(no subject)
By ROB GILLIES, Associated Press Writer 43 minutes ago
A giant ice shelf the size of 11,000 football fields has snapped free from
Canada's Arctic, scientists said. The mass of ice broke clear 16 months ago
from the coast of Ellesmere Island, about 497 miles south of the North Pole,
but no one was present to see it in Canada's remote north. Scientists using
satellite images later noticed that it became a newly formed ice island in
just an hour and left a trail of icy boulders floating in its wake.
Warwick Vincent of Laval University, who studies Arctic conditions, traveled
to the newly formed ice island and could not believe what he saw.
"This is a dramatic and disturbing event. It shows that we are loosing
remarkable features of the Canadian North that have been in place for many
thousands of years. We are crossing climate thresholds, and these may signal
the onset of accelerated change ahead," Vincent said Thursday.
In 10 years of working in the region he has never seen such a dramatic loss
of sea ice, he said.
The collapse was so powerful that earthquake monitors 155 miles away picked
up tremors from it.
The Ayles Ice Shelf, roughly 41 square miles in area, was one of six major
ice shelves remaining in Canada's Arctic.
Scientists say it is the largest event of its kind in Canada in 30 years and
point their fingers at climate change as a major contributing factor.
"It is consistent with climate change," Vincent said, adding that the
remaining ice shelves are 90 percent smaller than when they were first
discovered in 1906.
"We aren't able to connect all of the dots ... but unusually warm
temperatures definitely played a major role."
Laurie Weir, who monitors ice conditions for the Canadian Ice Service, was
poring over satellite images in 2005 when she noticed that the shelf had
split and separated.
Weir notified Luke Copland, head of the new global ice lab at the University
of Ottawa, who initiated an effort to find out what happened.
Using U.S. and Canadian satellite images, as well as data from seismic
monitors, Copland discovered that the ice shelf collapsed in the early
afternoon of Aug. 13, 2005.
"What surprised us was how quickly it happened," Copland said. "It's pretty
alarming. Even 10 years ago scientists assumed that when global warming
changes occur that it would happen gradually so that perhaps we expected
these ice shelves just to melt away quite slowly, but the big surprise is
that for one they are going, but secondly that when they do go, they just go
suddenly, it's all at once, in a span of an hour."
Within days, the floating ice shelf had drifted a few miles offshore. It
traveled west for 31 miles until it finally froze into the sea ice in the
early winter.
The Canadian ice shelves are packed with ancient ice that dates back over
3000 years. They float on the sea but are connected to land.
Derek Mueller, a polar researcher with Vincent's team, said the ice shelves
get weaker and weaker as the temperature rises. He visited Ellesmere's Ward
Hunt Ice Shelf in 2002 and noticed it had cracked in half.
"We're losing our ice shelves and this a feature of the landscape that is in
danger of disappearing altogether from Canada," Mueller said. "In the global
perspective Antarctica has many ice shelves bigger than this one, but then
there is the idea that these are indicators of climate change."
The spring thaw may bring another concern as the warming temperatures could
release the ice shelf from its Arctic grip. Prevailing winds could then send
the ice island southwards, deep into the Beaufort Sea.
"Over the next few years this ice island could drift into populated shipping
routes," Weir said. "There's significant oil and gas development in this
region as well, so we'll have to keep monitoring its location over the next
few years."
Copyright © 2006 The Associated Press. All rights reserved. The information
contained in the AP News report may not be published, broadcast, rewritten
or redistributed without the prior written authority of The Associated
Press.
Copyright © 2006 Yahoo! Inc. All rights reserved.
Questions or Comments
Privacy Policy -Terms of Service - Copyright/IP Policy - Ad Feedback